Oil burner



April ,194 L. LA BRANCHE 2.237.967

OIL BURNER Filed March 6, 1939 4 6 B 2 B 2 U 4 W ,2 a 3 2 fi w 2 0 00% 000 H 7 Q 00 I I 000 F 0% I 000% U 1 000 O| Z 000 r I 2 0 2 b c a v a, v 8 3. 5 m mu gm 5 Patented Apr. 8, 1941 UNITED STATES PATENT OFFICE 2,237,967 0151. BURNER I Louis La Branche, Dayton, Ohio Application March 6, 1939, Serial No. 260,051

7 Claims.

One of the several problems incidental to oil.

burners for domestic heating and for industrial use, is achievement of thorough and uniform combustion of fluid fuel and avoidance of soot and carbon deposits resulting from improper combustion. In the present instance, there is afforded ahighlyeiflcient burner which produces a clear blue flame of, high heat intensity by properly proportioned and distributed 'air supply for combination with the combustible components of fuel consumed.

The object of the invention is to improve the construction as well as the means and mode of operation of fluid fuel burners, whereby they may not only be economically manufactured, but will be more eflicient in use, uniform in operation, automatic in action, having fewparts and unlikely to get out of repair. l l

A further and important object of the invention is to provide more uniform and wider distribution of air for combination with the products of combustion, whereby the liquid or gaseous fuel will not only be more thoroughly and evenly consumed, but will burn with more intense heat by utilizing a greater proportion of the latent B. t. u. content of the'fuel.

A further object is to provide air in progressively increasing volume as the vaporization and expansion of combustible fuel products progresses.

A further important object of the invention is the generation of a clean blue flame in which the fuel components will becompletely consumed and production of soot and carbon avoided.

A further object ofthe invention is to provide a burner, all portions of which are easily accessible for inspection and observation of the operation, and which obviates entrapment pockets in which explosive products of combustion may collect, thereby insuring safety of operation,

A further object of the invention is to provide a burner for liquid or gaseous fuels possessing the advantageous structural features and inherent meritorious characteristics herein mentioned.

With the above primary and other incidental objects in view as will more fully appear in the specification, the invention intended to be protected by Letters Patent consists of the features of construction, the parts and combinations thereof, and the mode of operation, or their equivalents, as hereinafter described or illustrated in the accompanying drawing.

In the drawing, wherein is shown the preferred, but obviously not necessarily the only form of embodiment of the invention,

Fig. 1 is an exterior side elevation of an assembled burner embodying the present invention.

Fig. 2 is a perspective sectional view illustrating the interior of the assembled burner.

Fig. 3 is a top plan view thereof.

Fig. 4 is a plan view of the fuel receptacle unit.

Fig. 5 is a vertical sectional view of a modification.

Fig. 6 is a detail perspective view of a further modification.

Fig. 7 is a detail perspective view of a further modification.

Like parts are indicated by similar characters of reference throughout the several views.

While the present invention may be embodied in different forms of burner structure, for illusitrati-ve purposes, but with no intent to unduly limit or restrict the scope or application of the invention, it is herein illustrated in a simplified form comprising an annular channeled fuel receptacle l, having extending centrally therethrough an air flue 2, and surmounted and surrounded by a perforate chimney element 3. V

The outer wall of the annular fuel receptacle is disposed preferably, although not necessarily, in overhanging relation, either horizontally as in Fig, 2, or inclined as in Fig. 5, and is provided with a continuous succession of small spaced holes 5 in Fig. 2 and 5 in Fig. 5 in elevated relation above the bottom of the receptacle. The inner wall of the annular receptacle I defining the central air flue 2 of the fuel receptacle, terminates in a plane somewhat above the level of the outer wall perforations 5. A damper I in the flue 2 reg- =ulates the admission of air therethrough.

Communicating with ports 8 and 9 in the base of the fuel receptacle and thence through vertical ports l0 and H with the channel I! of the fuel receptacle, are a'fuel supply conduit l3 and an overflow conduit I4. Fuel is supplied by gravity feed or otherwise'as desired through the-conduit I3 and discharged through the port l0 into the channel l2. The overflow port H is in a nipple I5 projecting above the bottom of the channel which determines the maximum depth of fuel charge in the channel;

Any surplus fuel supplied through the conduit l 3 is drained from the channel through the overflow port and conduit I 4. Leading to the base of the member I is an additionalconduit [5 for ignition fluid which discharges intothe channel l2 through a port I! in a manner quite similar to the fuel supply conduit I3 and discharge port Distributed throughout the channel intermediate the respective inlet and outlet ports are a plurality of upstanding perforate air jet nipples I8, the passages of which communicate with an inverted channel I9 in the bottom of the unit I which is open to atmosphere. In lieu of single air jet nipples I8 in the bottom of the channel I2, these may be combined into'elongated prismatic elevations 20, which are longitudinally slotted for passage of air therethrough, as shown in Fig. 6.

Seated upon the top edge of the outer wall of the fuel receptacle is the chimney unit 3, which is of somewhat greater diameter than the fuel receptacle and projects laterally therebeyond. The chimney unit 3 is provided with an internal circumferential flange 2 I, which is rabbeted at 22 for seating engagement on the top of the fuel receptacle wall 4, and has therein a succession of spaced perforations 2B beyond the fuel unit wall. The chimney extends quite some distance above and below the plane of the interior flange 2I, forming therebelowa dependent skirt 24 surrounding in spaced relation the fuel receptacle unit I' and affording therebetween an annular air space 25 open to atmosphere at its bottom with which both the perforations 5 of the fuel receptacle I and the perforations 2B of the chimney flange 2| communicate. therein a succession of spaced holes 26 through which the annular air space 25 communicates with atmosphere at its top in addition to com- -munication therewith through its open bottom.

Above the level of the fuel receptacle unit I,

the chimney is provided with a relatively large number-of'small holes 2'! through which air may enter laterallydirectly to the interior of the chimney. Since the fuel oil admitted through the conduit I3 and port II] to the channel I2 does not readily ignite when starting operation of the burner, a small quantity of more volatile and inflammable priming liquid is admitted to the channel through the conduit I6 and port I! to insure ignition. The liquid fuel Within the ch'annel is consumed, leaving but little, if any, residue.

The visible zone of combustion begins at the top of the unit I substantially in the plane of or slightly above the holes 5 in the outer wall 4, and contiguous to the top of the flue 2. Ordinary commercial grade of fuel oil burns with a clear, steady blue flame thence upwardlythrough the chimney substantially filling the latter. The combustion is complete, leaving no noticeable deposits of soot or carbon. Merely for explanatory purpose, and with no intent to unduly limit or restrictthe invention in any way, it may 'be stated that the passages of the nipples I8 and the holes 23 in'the chimne flange 2| and holes 26 in the chimney skirt 24 are preferably made with a No. 32' drill. The holes 5 in the wall 4 of the unit I are made with a size 34 drill. The holes 21 in the chimney wall correspond to a size 29 drill. These holes'have been found in practice to be quite satisfactory when burning ordinary commercial fuel oil. These sizes may be varied somewhat without's'eriously aifecting'the burner operation when using such fuel. For other qualities or characters of fuel, it may be found necessary to vary either the number or the size of the holes.

The exact principle upon which the burner operates is not definitely known. It being appreciated that since the structure is amply described, the exact principle or theory of operation need The skirt 24 has,

not be stated, or even known, it is believed that the advantageous and benficial results are due to the more or less gradual intermixture of air with the products of combustion in relatively small portions, but in progressively increasing volume throughout succeeding combustion zones, somewhat proportionate to the increased volume of the expanded products of combustion.

Air is initially supplied in relatively small volume to the initial combustion line through the ports 5 and passages of the air jet nipples [8. Additional air in regulated quantities is admitted through the flue 2 by adjustment of the damper 1. Instead of being admitted in a large mass, the air supply is broken up into a large number of small jets which affords a more uniform distribution and even mixture.

As more fuel is volatilized by heat and the heated products of combustion expand, additional air is required to afford a highly combustible mixture. Additional air is supplied at a higher level through the ports 23 which are supplemental to the ports 5. The air entering through these ports 23 is baflled and to some degree preheated, and its velocity retarded to prevent undue turbulence by being drawn from the jacketed space 25.

As the gases and products of combustion become more diffused and expanded during passage through the second mentioned combustion zone, still more air is required for intermixture therewith into a combustible condition. The increased volume of highly heated gases and combustion products which then fill the chimney chamber is supplied through the holes 21 in the chimney wall with atmospheric air in considerable volume, but again divided into relatively small portions which are widely and thoroughly distributed and intermixed with the fuel vapors and gases in the upper portion of the burner. As a result of such successive stages; of combustion, each with increased air supply uniformly distributed in intermixture with the combustible fuel, vapors and gases, the waste of fuel is reduced to minimum or entirely avoided, the heating capacity of the burner is vastly increased, and there are substantially no soot or carbon deposits.

While the burner has been herein described primarily as an oil burner for liquid fuel, it is to be understood that by properly proportioning the different groups of air inlet ports as to number and size, aseous fuels may also be utilized, and therefore the invention is not limited to the use of liquid fuel.

In Fig. 7, there is shown a slight modification, wherein a dependent baffle flange 28 is interposed between the air ports 5 and the upstanding air nozzles 20. This insures that an ample incoming air supply is directed below the zone of active combustion for immediate intermixture with the initial products of combustion. As the volume of products increases, additional air is supplied to the ever expanding body in proximate proportion to its expansion, but in sub-divided small increments which combine more uniformly and thoroughly intermix with the expanding volume of products of combustion. It is found that while there is a more or less definite ratio between the air and fuel supply, that the air supply should be progressively increased with the increase of products of combustion and in a proportionate relation thereto. It is also found that merely to combine large volumes of air and products of combustion is not efficient, but that the air suply should be more or less uniformly broken up or sub-divided and that the intermixture of air with the products of combustion should be uniforml distributed to insure continuing combustion of the initially freed fuel components. As a result of the present mode of operation, the combustible material released by the initial combustion continues to burn with increasing vigor as its volume expands and becomes intermixed with increasing volume of air. Thus substantially complete combustion is effected and carbon and soot deposits are minimized or completely obviated.

From the above description, it will be apparent that there is thus provided a device of the character described possessing the particular features of advantage before enumerated as desirable, but which obviously is susceptible of modification in its form, proportions, detail construction and arrangement of parts without departing from the principle involved or sacrificing any of its advantages.

While in order to comply with the statute, the invention has been described in language more or less specific as to structural features, it is to be understood that the invention is not limited to the specific features shown, but that the means and construction herein disclosed comprise the preferred form of several modes of putting the invention into effect, and the invention is therefore claimed in any of its forms or modifications within the legitimate and valid scope of the ap pended claims.

Having thus described my invention, I claim:

1. In a hydrocarbon fuel burner, a combustion section including an annular fuel receiving channel, a fuel supply conduit communicating therewith, a chimney section of greater diameter than the combustion section superposed thereon, an internal bottom flange in the chimney section extending beyond the combustion section, a dependent skirt on the chimney section enclosing an air space surrounding the combustion section, said combustion section having therein a series of air ports communicating with said enclosed air space, the interior bottom flange of the chimney section having therein a series of air ports also communicating with the said enclosed air space surrounding the combustion section, and said chimney section having in its side walls a plurality of air ports, the construction and arrangement being such that the interior capacity of the burner structure in spaced relation above the zone of combustion inception is substantially increased and the air supply thereto also increased by successive additional amounts in relatively small increments with relation to the increased volume of products of combustion.

2. A hydrocarbon fuel combustion unit including an annular fuel channel including an inturned outer wall, an air flue concentrically disposed within the annular channel, a series of relatively spaced air inlet ports in the outer wall, the air inlet ports being in elevated relation with respect to the bottom of the fuel channel and below the upper end of the air flue, a series of upstanding air supply nozzles within the fuel channel terminating short of the level of the air inlet ports in the outer wall of the fuel channel, a fuel supply conduit leading to the channel, and a, perforate chimney portion surmounting the combustion unit.

3. A hydrocarbon fuel burner including a recessed fuel unit, a fuel supply conduit leading thereto, a series of relatively spaced air ports in the outer wall of the recessed fuel unit, air inlet nozzles arising from the bottom of the recessed fuel unit and terminating below the level of the air inlet ports in the outer wall of the fuel channel, an air flue concentrically disposed with the fuel unit, and a dependent flange between the air ports in the outer wall and the air nozzles.

4. In a hydrocarbon fuel burner, a fuel unit, a fuel supply conduit communicating therewith, a chimney unit of greater diameter surmounting the fuel unit, a dependent skirt of the chimney unit surrounding the fuel unit in relatively spaced concentric relation affording an annular air space between the skirt and fuel unit, relatively spaced air inlet ports affording intercommunication between the said annular air space and both the fuel unit and the chimney unit and additional relatively spaced air supply ports in the side walls of the chimney unit.

5. In a hydrocarbon fuel burner, the combination with a fuel unit, and means for supplying fuel and air thereto, of a chimney unit surmounting the fuel unit including a perforated cylindrical portion of greater diameter than the fuel unit, an interior annular perforate bottom within the chimney unit extending circumferentially beyond the fuel unit, and a dependent skirt on the chimney unit surrounding the fuel unit and affording therebetween an annular air space communicating through relatively spaced air ports with the interiors of the fuel and chimney units, the volume capacity and air supply to the chimney unit being greater than those of the fuel unit.

6. In a hydrocarbon fuel burner, a combustion unit including an annular fuel receiving channel, a fuel supply conduit leading thereto, an air flue disposed concentrically within the annular fuel channel, the outer wall of the fuel receiving channel being inturned and having therein a series of relatively spaced air ports disposed below the discharge end of the air flue for supplying air subdivided into small increments at the plane of combustion inception, an enlarged perforate chimney unit surmounting the fuel receiving channel having therein multiple relatively small air inlet ports through which air is supplied in successive additional amounts as the products of combustion increase in volume, additional air inlet ports in the chimney unit the axes of which are parallel to the major axis of the unit, and baflle means overlying and shielding the additional chimney ports and those in the fuel receiving channel.

7. In a hydrocarbon fuel burner, a fuel receiving unit, a chimney section increasing in transverse dimensions in spaced relation above the zone of combustion inception resting thereon and including substantially upstanding side walls, an internal flange forming a partial bottom for the chimney section and extending laterally beyond the fuel receiving unit and a pendant skirt portion on the chimney section extending in surrounding spaced relation with the fuel receiving unit, said fuel receiving unit and chimney section having therein a plurality of small relatively spaced air inlet ports so disposed and arranged as to admit to the burner successive additional amounts of air as the products of combustion progressively increase in volume upward from the plane of combustion inception.

LOUIS LA BRANCI-IE. 

